1. Field of the Invention
The present invention generally relates to communication systems, and more particularly to a system and method for controlling call pick-up in a switching device of a communication system.
2. Background of the Related Art
FIG. 1 illustrates a call pick-up system of a switching device in the related art which executes a call pick-up system for subscribers of a call pick-up group 30. The system comprises multiple subscriber telephones 31 belonging to a call pick-up group 30; a subscriber process block 20 for interfacing with the telephones 31; and multiple subscriber call process blocks 10-1˜10-n for conducting call processes of telephones 31 through the subscriber process block 20.
Each of the subscriber call process blocks 10-1˜10-n comprises a call process common block 11 for processing subscriber operations; a LCD control block 12 for controlling a LCD (Liquid Crystal Display) and transmitting relevant information to the subscriber; a digit analysis block 13 for analyzing the digits dialed by the subscriber; and a ring search block 14 for searching for the subscribers whose phones are ringing.
FIG. 2 illustrates a call pick-up method in a switching device of the related art having the above-described structure. If the telephones of multiple subscribers belonging to a call pick-up group are ringed at the same time, the subscriber (e.g., call pick-up subscriber) dials the call pick-up feature code in order to execute the call pick-up. Then, the digit analysis block 13 analyzes the digits dialed by the subscriber. If the dialed digits match the call pick-up feature code, the digit analysis block 13 notifies the call process common block 11 of the match.
Thereupon, the ring search block 14, which is controlled by the call process common block 11, analyzes the status of the subscribers 30 belonging to the call pick-up group. In other words, the ring search block 14 identifies which subscriber's phone is ringing. If the ring search block 14 identifies the subscriber whose phone is ringing, the identity of the subscriber is notified to the call process common block 11.
The LCD control block, which is controlled by the call process common block 11, sends a message to the subscriber whose phone is ringing and informs the subscriber that the call can be picked up by another subscriber (i.e., a call pick-up subscriber). Then, the subscriber whose phone is ringing transmits a response message to the call pick-up subscriber.
Thereupon, the call pick-up subscriber analyzes the response message transmitted by the subscriber, identifies who the caller is, and notifies the identified caller of the call pick-up. Then, one-to-one communication takes place.
Now, the selective call pick-up process is explained. If the phones to multiple subscribers 31 belonging to the same call pick-up group 30 (e.g., the first ring subscriber and the second ring subscriber) ring at the same time, a call pick-up subscriber dials a call pick-up feature code to. execute the call pick-up.
Then, the digit analysis block 13 analyzes the digits dialed by the call pick-up subscriber. If the dialed digits match the call pick-up feature code, the digit analysis block 13 notifies the call process common block 11 of the match.
The ring search block 14 analyzes the status of subscribers' phones 31 belonging to the call pick-up group 30. Then, all of the subscribers, whose phones are ringing, are identified (e.g., the first ring subscriber or second ring subscriber).
When the ringed subscribers (e.g., the first ring subscriber and the second ring subscriber) are identified by the ring search block 14, the information of these subscribers (e.g., the first and second ring subscribers) is transmitted to the call process common block 11.
Through the LCD control block 12, the information of the subscribers (e.g., the first and second ring subscribers) is displayed on the telephone LCD of the call pick-up subscriber. At this time, the LCD control block 12 assigns an ID (Identifier) number to the ringed subscriber's phone.
Thereupon, the call pick-up subscriber uses the information displayed on the telephone LCD (i.e., the ID number) to designate a specific subscriber (e.g., the first ring subscriber or the second ring subscriber). Thus, the specified subscriber (e.g., the first ring subscriber or the second ring subscriber) is notified of the call pick-up subscriber.
The specified subscriber (e.g., the first ring subscriber or the second ring subscriber) then transmits a response message to the call pick-up subscriber. The call pick-up subscriber analyzes the response message and finds out who the caller is (e.g., the first caller or the second caller), and notifies the caller (e.g., the first caller or the second caller) of the call pick-up. Then, one-to-one communication takes place.
As described above, in the call pick-up system of the switching device of the related art, there are two cases of call pick-up: In the first case described above, the subscriber whose phone is ringing cannot be selected; and in the second case described above, selective call pick-up is possible by using the information of the subscribers whose phones are ringing. According to the call pick-up technology of the related art, when a call pick-up feature code is dialed, a call pick-up takes place automatically.
Accordingly, in the related art, it is impossible to conduct a selective call pick-up based on the caller's information, such as the caller number or the caller name. Further, it is impossible to choose to accept or refuse the call based on the caller's identity.